Article Distribution

It depends on the niche and the product etc.
If you can get a prime article onto ezine articles then you can get a ton of traffic that way.
You need to create a plan for how you will funnel traffic.
Do you want to get people to read your article and then close them on your website?

Personally, I really do not think you need to write a 100 different articles for one product.

A good dozen or so, should satisfy the need for traffic.

I agree with LondanPaladin that you need a plan.
What you really should do, is look up some keywords you may want to optimize in your blog and article.

After, that create some variation of these keywords so that you can submit different variations of articles to different article databases.

Also, I agree Ezine Articles is a nice place for a prime spot.
If you are trying to get organic SEO traffic from Google, another option you may want to look at for advertising your product is UsFreeAds,

This site is a classified ad site, where you can post ads on your product, but I really like this site, because you can play with the HTML coding etc. to really optimize certain keywords, It is very useful for a Classified Ad Site.

Finally Forum Marketing would also be helpful in creating back links to your blogs or articles.

This is why I personally think a dozen or so unique articles should suffice if other marketing techniques are used in sync with article marketing.

Depends, Some of the products needs article on every 5 days, but at least one article is required for a product, per month or a little update, otherwise people may think that it's outdated.

Also if you're short of time you could sub the work out....

What I would do is write 4 o 5 articles per day. Post the blog content or article to the blog then submit them to articles directories. Well of course, submit it first to ezine before you submit to other article directories.

From my experience, you need several hundreds of articles to get significant traffic. And a good idea is to first post them on your site, then post to Ezines, then once approved, to other article directories.

Another question is whether you need those articles for traffic from the articles, or for backlinks as well? If for backlinks too, then I suggest you focus on "money keywords" on your blog / website, and "traffic keywords" for the articles. For example, if you have a site promoting "fat loss 4 idiots" diet, then for the site, you can optimize content for keywords like "fat loss for idiots review", "calorie shifting diet review", etc., while for the articles, you would optimize for "how to lose weight in 2 weeks", "need to lose weight for the wedding", etc.

Good luck!